Remove unneded memory_pressure benchmark and measurement. (Take 2)

BUG=440101

Review URL: https://codereview.chromium.org/798773002

Cr-Commit-Position: refs/heads/master@{#308165}

tools/perf/benchmarks/memory_pressure.py

-# Copyright 2013 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-from telemetry import benchmark
-from measurements import memory_pressure
-import page_sets
-
-
-@benchmark.Disabled
-class MemoryPressure(benchmark.Benchmark):
-  test = memory_pressure.MemoryPressure
-  page_set = page_sets.Typical25PageSet
-  options = {'pageset_repeat': 6}

tools/perf/measurements/memory_pressure.py

-# Copyright 2013 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-"""Multi tab memory test.
-
-This test is a multi tab test, but we're interested in measurements for
-the entire test rather than each single page.
-"""
-
-import logging
-
-from telemetry.value import histogram_util
-from telemetry.page import page_test
-
-
-class MemoryPressure(page_test.PageTest):
-  def __init__(self, *args, **kwargs):
-    super(MemoryPressure, self).__init__(*args, **kwargs)
-    # _first_tab is used to access histograms
-    self._is_first_page = True
-    self._tab_count = 0
-
-  # Allow histogram collection
-  def CustomizeBrowserOptions(self, options):
-    histogram_util.CustomizeBrowserOptions(options)
-
-  # Open a new tab at each page
-  def TabForPage(self, page, browser):
-    return browser.tabs.New()
-
-  def GetTabsHistogramCounts(self, tab):
-    histogram_type = histogram_util.BROWSER_HISTOGRAM
-    discard_count = histogram_util.GetHistogramCount(
-      histogram_type, "Tabs.Discard.DiscardCount", tab)
-    kill_count = histogram_util.GetHistogramCount(
-      histogram_type, "Tabs.SadTab.KillCreated", tab)
-    return (discard_count, kill_count)
-
-  def ValidateAndMeasurePage(self, page, tab, results):
-    # After navigating to each page, check if it triggered tab discards or
-    # kills.
-    (discard_count, kill_count) = self.GetTabsHistogramCounts(tab)
-
-    # Sanity check for first page
-    if self._is_first_page:
-      self._is_first_page = False
-      assert discard_count == 0 and kill_count == 0
-
-    self._tab_count += 1
-    # End the test at the first kill or discard.
-    if kill_count > 0 or discard_count > 0:
-      logging.info("test ending at tab %d, discards = %d, kills = %d" %
-        (self._tab_count, discard_count, kill_count))
-      self.RequestExit()